My favorite tumbler is from a gun supply named Midway. model1292 sells for 45 dollars. The thinner walls do NOT wear out. They wear like iron. They do say not to use liquids, but with a little caution so it doesn't get into the motor , it works like a charm.
Dear Richard, please do take care for these type of tumblers because
they may overheat while they are working and may cause a fire. This
has been announced by CPSC quite a while ago, kindly visit this
site: http://www.safetyalerts.com/rcls/cpsc/pr/98/98088.html
Always check your work and mostly the tumbler whilst tumbling or
else return it for inspection. Regards,
JOSEPH TANTI
MALTA
http://jostanti.cjb.net